Aluminum alkyls from non-alpha olefins

ABSTRACT

Alkyl aluminium compounds are prepared by treating a non-a -olefin (as defined) with a low molecular weight alkyl aluminium compound (as defined) using as catalyst a compound of Groups IV(a), V(a), VI(a) (i.e. Ti, V and Cr groups).  The non-a -olefin is defined as an olefinic hydrocarbon or mixtures thereof wherein at least 40% of the molecules have a non-terminal olefinic double bond.  The mixture may contain up to 50 mol. per cent of olefins of chain length equal to or less than that of one or more of the alkyl groups of the aluminium compound.  The alkyl aluminium compound is defined as having alkyl groups with fewer carbon atoms than the non-a -olefin employed in the process and may have one or two H atoms attached directly to aluminium.  The catalyst may be a halide preferably the chloride and/or a compound having an oxygen atom linking the metal with a carbon atom.  More particularly the catalyst may be an alcoholate, a chelate, or a phenolate e.g. methylates, ethylates, propylates, isopropylates, phenolates, cresolates, acetylacetonates, salicylates, benzoylacetonates, 2-furoylacetonates; of Ti, Zr, V, U, Cr, Th, W, Ta, or Nb.  The low molecular weight alkyl aluminium compound is preferably tri-isobutyl aluminium but may also be tri-ethyl, propyl or n-butyl aluminium, di-isobutyl aluminium chloride or diethyl aluminium hydride, the preferred compounds having alkyl groups containing at the most 4 C atoms. The non-a -olefins suitable for the process are but-2-ene, pent-2-ene, hex-3-ene, oct - 2,3 or 4 - ene, dec - 5 - ene, tridec-6-ene but preferably having at least 6 C atoms. The non-a -olefin may be obtained (a) by dehydration of an alcohol or mixture of alcohols; (b) by thermal or catalytic cracking of hydrocarbon feedstocks (c) from the residue left after removal of a -olefins by polymerizing with a Ziegler catalyst.  The non-a -olefin and the low molecular weight alkyl aluminium compound may be used in molar ratio 1.5: 1 to 10: 1 and the catalyst in amount 0.05 to 10% but preferably 0.5 to 5% mol.  The reaction temperature may be 50-250 DEG  C. but preferably 100-150 DEG  C. whilst preferred reaction conditions are 0.1 to 2% mol. of catalyst at a temperature of 150-200 DEG  C. In examples 1-3, 1-octanol is dehydrated with 100% phosphoric acid and the octenes mixed with tri-isobutyl aluminium. TiCl4 was added to the mixture, which was then heated and the isobutene produced collected in a cold tap.  In other examples various octenes are used whilst examples 15-53 relate to various catalysts used in processes involving octenes.  Primary alcohols are made by the oxidation of the alkyl aluminium compound prepared as above, to form an aluminium alcoholate followed by hydrolysis of the alcoholate.  In an example the reaction product from a mixture of non-a -octenes is oxidized by bubbling in air and then hydrolyzing with 10% hydrochloric acid, to give 1-octanol after separation and purification. The preparation of 1-octanol is exemplified using various catalysts and starting materials.  Specifications 827,901, 941,016 and 993,666 are referred to.

3,322,806 ALUMINUM ALKYLS FROM NON-ALPHA ()LEFINS This invention relates to the preparation of primary alcohols from internal olefins. More specifically, it relates to the catalytically accelerated reaction of aluminum trialkyls with non-a-olefins and the subsequent conversion of the resulting exchanged aluminum trialkyls to corresponding alcohols.

Higher normal primary alcohols are particularly useful as detergent intermediates. They may be obtained through a series of reactions, the first of which involves the production of suitable aluminum alkyls by reacting higher olefin with aluminum tri (lower alkyl), e.g., aluminum triisobutyl. The higher olefin displaces one or more of the lower alkyls. Subsequent oxidation of the resulting alumi num trialkyl with, for instance, air produces the alkoxide which in turn can be hydrolyzed with, e.g., water or dilute acid to obtain the higher primary alcohol. This process for the production of primary alcohols has been limited by the fact that the initial displacement reaction between the lower aluminum alkyls and the higher olefins only proceeds at a satisfactory rate when the olefin involved is an a-olefin. Displacement with a non-a-olefin has been too slow for practical use.

It is, therefore, a principal object of the present invention to provide an efficient and economical method for effecting exchange between aluminum trialkyls and nonu-olefins and to produce primary alcohols from the 11011-06- olefins.

These and other objects will be better understood from the description of the invention as given hereinafter.

Now, in accordance with this invention, it has been found that IlOll-Ot-OlEfiHS readily react with aluminum alkyls in the presence of certain materials which catalyze the reaction. It has now been found that compounds of certain transition metals catalyze the reaction to such a degree that use of none-olefins in the displacement reaction becomes commercially feasible. The process comprises therefore reacting a non-a-olefin with an aluminum lower alkyl in the presence, as catalyst, of a compound of a metal of groups IVB, V-B, or VI-B of the periodic table of elements that is a metal on the left hand side of Groups IV, V, and VI of the table given, for example, on pages 54 and 55 of Lange Handbook of Chemistry, 10th edition (1961), McGraw-Hill Book Company.

By aluminum lower alkyl is meant an aluminum alkyl of which all the alkyl groups have fewer carbon atoms than the non-ot-olefin employed in the process. The aluminum lower alkyl may be an aluminum alkyl hydride. In that case, the l'lOIl-Ot-Olfifill converts the aluminum hydride group to an aluminum alkyl group.

Catalysts with which surprisingly good results have been obtained include compounds of zirconium, uranium, vanadium, chromium, thorium, and tungsten, with titanium being especially preferred. The catalyst may be added to the reactants in various forms, e.g., as a halide, especially a chloride such as titanium tetrachloride.

Further improvement has been found to result if the group IV-B to VIB metal catalyst is added in the form of a compound containing an oxygen atom linking the 3,322,806 Patented May 30, 1967 metal with a carbon atom, such as alcoholate, phenolate or a chelate. Suitable compounds of this type are the methylates ethylates, propylates, isopropylates, phenolates, cresolates, acetylacetonates, salicylates, benzoylacetonates, and Z-furoylacet-onates, with alcoholates and chelates of B-diketones such as the acetylacetonates being the most preferred.

Examples of the aluminum lower alkyls starting materials contemplated by this invention are aluminum triethyl, -tripropyl, -tri-n-butyl, -triisobutyl, -diisobutylmonochloride, and -diethylhydride, the preferred compounds having alkyl groups containing fewer than five carbon atoms. A particularly preferred starting material is aluminum triisobutyl.

The non-a-olefins, also called internal olefins, to be used in accordance with this invention contain a number of carbon atoms which is greater than the number of carbon atoms of any of the alkyl groups of the aluminum low alkyl. Suitable non-a-olefins include: butene-2, pentene-2, hexene-2, or -3, octene-Z, -3 or -4, decene-S and tridecene- 6. These may be obtained by, e.g., the dehydration of suitable alcohols or alcohol mixtures. Advantageously, a mixture of technical non-a-olefins is used, which preferably contains at least 6 carbon atoms per molecule. It is to be understood that Where a mixture of olefins is used, such as a mixture of technical olefins obtained by distillation, a small proportion of shorter chain length olefins may be present which are of a chain length equal to or less than that of one or more of the alkyl groups of the aluminum alkyl. Therefore, included in this invention is the use of olefin mixtures containing shorter chain length olefins, provided that these shorter chain olefins do not pre dominate.

Technical olefins having a high a-olefin content may be obtained by thermal or catalytic cracking of hydrocarbon feedstocks, e.g., the wax fractions produced in dewaxing luboils, or the rafiinate obtained by the selective solvent extraction of heavy catalytically cracked cycle oil, or the n-paraflins separated from straight-run kerosene and gasoil fractions by urea or molecular sieve fractionation to lower the pour point. Such olefins are usually fractionated into distillation cuts containing e.g. C -C C C C C and C14C1B olefins. The DL-OlefiHS in such mixtures are much more reactive than the non-a-olefins. Thus, when polymerizing such olefin mixtures, the a-olefins react preferentially and the non-a-olefin content in the unreacted olefinic residue increases extensively. Thus a product may be fractionated from this residue which is predominantly internal olefin and particularly useful in this invention.

In the practice of this invention, the molar ratio of V I10n0-0l6fin to the relatively low molecular weight alkyl aluminum may suitably vary from 1.5:1 to 10:1 or more. By non-u-olefin is meant an olefinic hydrocarbon or a mixture of such hydrocarbons having the olefinic double bond in a position other than a terminal one in a substantial proportion of the molecules, in particular one in which at least 40% of the molecules and preferably at least 60%, have the olefinic double bond in a non-terminal position.

In carrying out the process, the compound of the Group IV-B, V-B or VI-B metal is added to the reaction mixture in catalytic amounts, i.e., in an amount which may vary from, e.g., 0.05 to 10 mole percent, in particular from 0.5 to 5 mole percent, based on the amount of relatively lower alkyl aluminum compound employed. Smaller or larger amounts may be used, of course, if desired. Suitably the catalyst may be mixed With the olefin after which the relatively low alkyl aluminum compound is added.

Suitable reaction conditions for the preparation of aluminum alkyls acording to the invention includes tem- 3 peratures from 50 to 250 C., preferably from 100 to 150 C., the reaction being conveniently carried out under an inert atmosphere, such as argon. It has been found .that at high temperatures smaller amounts of catalyst 4 it, then hydrolyzed with 10% aqueous hydrochloric acid. After separation of the organic phase the aqueous phase was twice extracted with ether. The organic phase and the extracts were dried over sodium sulphate. The ether,

and shorter reaction times are required. Thus, it has been 5 isobutanol and octenes were distilled off employing a found that at reaction temperatures between 150 and short rectifying column. The residue was vacuum-distilled 200 the optimal amount of catalyst can be decreased to yielding a fraction boiling at 9295 C. containing oc- 0.1-2 mole percent. A reaction time of 5-10 hours will tanol-l as determined by gas chromatography. generally be sufiicient at temperatures between 100 and Table I contains a summary of the data from the fore- 150 C., while between 150 and 200 C. reaction times going example (Run 1) as well as from Runs 2-14 in of %5 hours may be used. At temperatures above 180 C. which molar ratios and conditions were varied as indisome catalyst systems tend to decompose. cated. Control Run x was conducted in the absence of Although atmospheric pressure is preferred, variations the transition metal catalyst. in pressure have no adverse effect on the reaction; sub- The use of oetene-l as the starting olefin under the atmospheric or superatmospheric pressures can be used. above conditions resulted in the formation of no octanol, The aluminum alkyl produced according to the inventhe product obtained being a rubbery mass, resulting tion can be converted into a variety of derivatives by refrom polymerization of the a-olefin.

TABLE I Reaction Al-tri- Catalyst Isobutene Yield of Yield of Example isobutyl, T1014, Octenes collected, Oetanols, Octanol-l, mole mole percent Time, Temp, percent b percent 6 hrs. 0.

5 Based on aluminum triisobutyl, isobutane collected in cold trap.

b Based on octenes charged. 8 Based on octenes converted.

d Octenes obtained by dehydration of octanol1 over phosphoric acid.

= Octene-2 obtained by Grignard reaction of crotyl chloride with butyl chloride. f Diisobutylaluminum hydride. s 2 m1. T1014 added dropwise during reaction. 11 Catalyst added in two portions.

i ml. toluene added. i Trans-n-oetene-t.

action with, e.g., S0 producing sulphinic acids, or with CO resulting in the formation of carboxylic acids. Preferably the aluminum alkyls are oxidized, e.g., with oxygen, to form the corresponding aluminum alcoholates. Subsequently the alcoholates are hydrolyzed to form the corresponding primary alcohols.

The following specific example of the invention will serve to illustrate more clearly the application of the invention, but it is not to be construed as in any manner limiting the invention thereto:

Example I The olefin starting material was prepared by dehydration of n-octanol-l over 100% phosphoric acid. It contained less than 10% octene-l, the remainder being nona-octenes. These octenes and aluminum triisobutyl were mixed in the molar ratios, indicated in Table I, at room temperature in a three-neck flask flushed with argon and provided with a reflux condenser, stirrer and gas inlet tube. Subsequently, TiCL; was added drop by drop. A vigorous reaction took place while the reaction mixture became dark brown and the temperature rose 5 C. The mixture was heated to 105-1-35 C. and stirred for a period as indicated in Table I. Evolved isobutene was collected in a cold trap (80 C.). The reaction mixture was completely oxidized by bubbling air through Example [I In the following series of experimental Runs 15-46 as set out in Table II below, the olefin starting material was prepared by dehydration of a straight chain octanol, e.g., n-octanol-1 over phosphoric acid. For purposes of comparison, no catalyst was employed in Run Y. The resulting octene product contained about 2% octene-l, the remainder being non-a-octenes. 0.595 mol of this mixture of octenes, the catalyst (indicated in Table II) and subsequently 0.198 mol of aluminum triisobutyl were mixed at room temperature in a three-neck flask flushed with nitrogen and provided with a reflux condenser, cold trap, stirrer and gas inlet tube. A reaction took place during which the reaction mixture became dark brown and the temperature rose 5 C. The mixture was heated to a specified temperature and stirred for a specified time as indicated in Table II. Isobutene was collected in the cold trap ('80 C.). The reaction mixture was completely oxidized by bubbling air through it and then hydrolyzed with 10% hydrochloric acid. After separation of the organic phase the aqueous phase was twice extracted with ether. The former phase and the extracts were dried over sodium sulphate. The ether, isobutanol and octenes were distilled off employing a short rectifying column. In the residue the octanol-l content was determined by gas chromatography.

TABLE II Amount of Cat. Example Catalyst Time, Temp, Yield of hrs. C. Octanol-L M01 M01 percent mol percent 2. 3 9 110 24 2. 3 7 110 38 2. 3 7 110 48 2. 3 7 110 48 2. 3 7 110 44 12. l 7 110 30 4. 9 7 110 44 3. 7 7 110 47 3. 7 110 60 2. 4 7 110 55 2. 3 7 110 48 0. 7 110 39 2. 4 9 140 44 2. 4 1 190 c 41 0. 25 6 170 52 0.25 6 200 44 3. 2 9 110 8 2. 3 7 110 2. 2 7 110 33 2. 3 7 110 55 2. 45 l 110 47 6 170 2. 3 7 110 10 2. 3 7 110 40 2. 3 7 110 29 0. 0045 2. 3 7 110 35 V(III)acetylacetonate 0.0045 2. 3 7 110 50 W61 0. 0045 2. 3 7 110 6 0.0135 6.8 7 110 16 0. 0045 2. 3 7 110 40 O. 0045 2. 3 7 110 35 0. 0045 2. 3 7 110 27 0.0045 2. 3 7 110 22 1! Based on Al-tri-isobutyl charged. b Based on octenes charged. 0 Charged 1.19 mole octenes, 0.198 mole Al-triisobutyl.

Example 111 A third series of experiments were carried out with the process described in Example I. The results are set tively low molecular weight aluminum alkyl compound employed.

2. A process in accordance with claim 1 in which the catalyst is a compound containing an oxygen atom linkout in Table III as experimental Runs 47-53. 40 ing the metal with a carbon atom.

TABLE III Catalyst Reaction Al-tri- Octenes Yield of Yield of Example isobutyl, mol Octanols, Octanol-l,

11101 Type Mol 'Ifime, Tergp, percent a percent b 0. 117 6 0. 352 Zr(IV)-acetylacetonate. 0.001 9 113 35. 9 91. 3 0. 117 0. 352 ZrCl-r 0. 002 8 110 40. 2 93.8 0. 117 0. 352 Z1 1 0. 0013 8 110 23. 9 70. 7 0. 117 0. 352 Zr(IV)aeetylacetonat 0.001 8 110 31. 3 86. 5 0. 117 '0. 352 0. 0041 8 110 42. 4 95. 9 0. 117 0. 3552 V(III)acetylacetonate 0.0014 8 110 42. 4 81. 4 0. 117 0.352 Vanadyldiacetylacetona 0. 0019 8 110 42. 0 81. 9

* Based on octenes charged. b Based on octenes converted.

u Octcne-2 obtained by Grignard reaction of crotyl chloride with butyl chloride.

d Trans-11'octene4. e Cis-n-octcne-4. f Octencs obtained by dehydratlon of octanol-l over phosphoric acid.

The yields in Table I]1I have been expressed in terms of the primary alcohol resulting after subsequent oxidation and hydrolysis of the higher molecular weight aluminum alkyl produced. The percent of conversion of the lower molecular aluminum alkyls would be even greater were the data based on the amount of higher aluminum alkyl obtained rather than on the primary alcohol formed.

We claim as our invention:

1. A process for the preparation of an aluminum n-alkyl which comprises reacting a linear non-u-olefin with a relatively low molecular weight aluminum alkyl compound in the presence of a catalyst comprising a compound of a metal of Group IV-B, V-B, or VI-B of the periodic table of the elements in an amount of 0.05 to 10 mole percent, based on the amount of said rela- 3. A process in accordance with claim 2 in which the catalyst is an alcoholate.

4. A process in accordance with claim 1 in which the catalyst comprises titanium.

5. A process in accordance with claim I in which the relatively low molecular weight alkyl aluminum compound is aluminum t riisobutyl.

6. A process in accordance with claim 1 in which the non-a-olefin contains at least 6 carbon atoms per molecule.

7. A process in accordance with claim 1 in which the non-u-olefin and the lower molecular weight alkyl aluminum compound are included in a molar ratio between 1.5:1 and 10:1.

8. A process in accordance with claim 1 in which the catalyst is added in an amount from 0.5 to 5% mol.

9. A process in accordance with claim 1 in which the reaction temperature is between 100 and 150 C.

10. A process in accordance with claim 1 in which the 5 non-a-olefin is an olefinic reaction residue containing more than 40% I10l'1-cc-0l6fins obtained by preferentially reacting the a-olefins of a collected hydrocarbon feed structure.

No reference cited.

TOBIAS E. LEVOW, Primary Examiner. 

1. A PROCESS FOR THE PREPARATION OF AN ALUMINUM N-ALKYL WHICH COMPRISES REACTING A LINEAR NON-A-OLEFIN WITH A RELATVELY LOW MOLECULAR WEIGHT ALUMINUM ALKYL COMPOUND IN THE PRESENCE OF A CATALYST COMPRISING A COMPOUND OF A METAL OF GROUP IV-B, V-B OR VI-B OF THE PERIODIC TABLE OF THE ELEMENTS IN AN AMOUNT OF 0.05 TO 10 MOLE PERCENT, BASED ON THE AMOUNT OF SAID RELATIVELY LOW MOLECULAR WEIGHT ALUMINUM ALKYL COMPOUND EMPLOYED. 